Hand held knives have been used for centuries by hunters, craftsman and others requiring a sharpened blade for various purposes. Most early knives were non folding fixed blade knives, which are potentially dangerous due to the exposed blade which must be sheathed when not in use. These knives are additionally quite cumbersome when attached to a belt due to their significant length.
Hand held folding knives are characterized by the knife blade pivoting about the knife handle from a first extended position of use to a second closed position wherein the cutting portion of the knife blade is stored within a knife cavity positioned within the knife handle. These knives are generally much less cumbersome than fixed blade knives and are much safer to carry and store since the sharpened cutting edge is not exposed.
More recently, hand held folding knives have been made with a multiplicity of blades and accessory tools stored within the knife handle cavity. An example of this type of knife is the well-known "swiss army knife." These types of knives and multi-tools have become increasingly popular since a variety of different types of knife blades and accessory tools can be stored within one common handle. Unfortunately, the knife blade and other accessory tools utilized on these types of knives are very difficult to open and often do not have any type of locking mechanism. Those knives which do have locking mechanisms are often difficult to extend from a closed position to a position of use and can be potentially dangerous if the blade is not securely "locked" in a position of use, thus preventing inadvertent claims on a user's hand.
One recent example of a folding knife with dual blades and having interrelated locking mechanisms is disclosed in U.S. Pat. No. D391,465 to Glesser. This design encompasses a "back lock" locking mechanism for each blade which must be depressed by a user's finger to release the blade from an extended position of use. The back locks are positioned proximate to an upper edge of the knife handle. Unfortunately, the back lock release mechanisms are immediately adjacent one another, thus making it difficult to release one blade at a time with a user's finger. Furthermore, the positioning of the release mechanisms is problematic since for both blades the release mechanisms are positioned too close to the respective folding blade, thus providing very little leverage to release the locking mechanism. Finally, this type of dual locking mechanism provides insufficient rigidly for the knife handle during use of the knife blades and thus requires a shim plate on other similar device to reinforce the handle.
Thus, there is a need for a type of locking mechanism used in conjunction with multi-bladed folding knives which can be quickly and effectively located and activated by a user's finger. Further, the release mechanism must be positioned in a location which provides significant leverage and thus allows the efficient release of the blade from a locked extended position to a released position for storing the blade in the knife handle cavity.